(i) Field of the Invention
The present invention relates to the field of atmospheric analysis equipment, and quite particularly deals with the case in which it is necessary to analyze one or more elements of an atmosphere at a plurality of points of an enclosure employing this atmosphere, or of a gas distribution network, this being in multiplexing mode (batch mode: sequential analysis of the points in an order which may be varied and with an addressing time for each measurement point which can also be varied).
(ii) Description of Related Art
These analysis applications fall within a context in which users of industrial gases (heat treatment, electronics, food, etc.) increasingly frequently need to analyze one or more components of the atmosphere which they are employing in a given user station, or alternatively one or more impurities (such as oxygen or alternatively water vapor) of a distributed gas before it is injected into their process, this being so as to be capable of carrying out comprehensive quality control on the articles being processed, this comprehensive quality control presupposing that it is possible to know the atmospheric conditions under which each article has been processed.
Customers using gases therefore often wish to be able to know these atmospheric conditions, or to display and archive them, with trackability, or even to process these values thus archived.
It can therefore be seen that the possibility should be available of providing these customers, who use industrial gases, with analysis methods and equipment allowing gas samples to be taken at the various analysis points which are monitored (whether these are various points of an enclosure employing the atmosphere for a given treatment, or various analysis points on a gas distribution network), making it possible:
to minimize the response time of the analyzer or analyzers in question; PA1 to ensure that the analysis bay is provided with samples of gas to be analyzed which are representative of the atmosphere of the enclosure or of the gas flowing in the distribution network to be analyzed, and in particular, as will be understood, in the case when the analysis bay is far away from the tapping points; PA1 to take samples and carry out analyses irrespective of the order of each measurement point; PA1 to take samples and carry out analyses whatever the addressing time of a given measurement point, depending on the species analysed and the type of analyzer employed. PA1 For such multiplexing applications, it has been proposed to use rotary valves based on stepwise advance of the valve, which becomes positioned in turn in front of each channel to be analysed. The use of such rotary valves is not, however, without its drawbacks, in particular linked with complex hardware, whose operational robustness remains to be proven, but above all for which a very precise rotational advance order needs to be adhered to. PA1 at least two sources of initial gases to be analyzed; PA1 at least two tapping lines, each line being connected in its upstream part to one of the initial gas sources, and in its downstream part to a respective flow-directing component; PA1 at least two discharge lines, each discharge line being connected in its upstream part to one of the directing components and in its downstream part to a discharge or to a storage point; PA1 at least two secondary lines, each secondary line being connected in its upstream part to one of the directing components and, in its downstream part, to a collecting point, each directing component being capable of directing a sample from the initial gas source which is associated with it to its respective discharge line or to the collection point via its respective secondary line; PA1 a tertiary line, connected in its upstream part to the collection point and in its downstream part to a discharge or to a storage point; PA1 at least one analysis line, connected in its upstream part to the tertiary line and in its downstream part to at least one of the at least one analyzers. PA1 a pumping component, located between the collection point and the point of connection between analysis line and tertiary line; PA1 the tertiary line includes a non-return valve downstream of the point of connection of the analysis line to the tertiary line; PA1 the tertiary line includes an overflow downstream of the point of connection of the analysis line to the tertiary line, and the analysis line or at least one of the analysis lines is provided with a component for creating a pressure head loss; PA1 the discharge line or at least one of the discharge lines is provided with a pumping component; PA1 the or each analysis line is provided with a directing component which makes it possible, depending on the case, to direct a calibration gas or a purging gas to the analyzer of the gas to be analysed; PA1 the directing component or components consist of a three-way solenoid valve; PA1 the directing component or components of the tapping lines consist of the assembly formed by the point of connection of the associated tapping, discharge and secondary lines, each secondary and discharge line being provided, downstream of this point, with a component capable of allowing or interrupting the flow of gas through the line in question; PA1 the initial sources to be analyzed are at a pressure above atmospheric pressure; PA1 the initial sources to be analyzed are at a pressure substantially equal to atmospheric pressure or below atmospheric pressures; PA1 the initial sources consist of gas samples taken from a distribution network; PA1 the initial sources consist of gas samples taken from various points of an enclosure employing a gas atmosphere; PA1 the installation includes a plurality of analyzers, the analysis lines being connected to the tertiary line at a feed tank; PA1 the installation includes a single analysis line connecting the tertiary line and the analyzers arranged in series; PA1 the installation includes one analysis line per analyzer.